php下载文件，用错了

今需要在页面下载文件，就找了个php的方法

public function _downloads($path){

        $filename = basename($path);

        $dirname  = dirname($path);

        if(!file_exists($path)){

            Header("Content-type: text/html; charset=utf-8");

            echo "file $path does not exist";

            exit();

        }else{

            $file = fopen($path,'r');

            Header("Content-type: application/octet-stream");

            Header("Accept-Ranges: bytes");

            Header("Accept-Length: ".filesize($path));

            Header("Content-Disposition: attachment; filename=".$filename);

            echo fread($file,filesize($path));

            fclose($file);

            exit();

        }

    }

以ajax方式调用，怎么都下载不了，后来明白了，直接用js就行了，这样调用也是错误的

window.location.href = path;

就这样一句js就搞定了，感到自己知识浅薄啊，。。。